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Video locks (with artifacts)/Monitor shuts off/System still running. Whats wrong?

By SNGX1275
Mar 3, 2005
  1. Ok got a problem that I think I knwo what is wrong, but I'm not sure. Looking for some confirmation on what I think. Or suggestions on what else if you disagree with my diagnosis.

    Computer in question:
    1 Ghz Duron
    ECS K7S5A
    256 of some ddr ram
    TNT 2 32 meg vid card

    I get a call from this lady and she says her computer locks up while on the internet and then the screen goes blank. When she turns it off and back on nothing happens. If she tries it later it will turn on but when she's on the internet it happens again.
    So thats the diagnosis she gave me.

    Today after work I stopped by her house and used the computer for a bit. She is running WinXP Pro SP1. I checked her antivirus, it needed updating but the defs weren't real old. I then looked in the event viewer, it was clean, no warnings or anything, only the information messages.

    So right now I'm thinking wtf? everything seems ok to me that would cause black screens. So I decide to fire up adaware (because I'm about to head out and thinking I might as well clean up the crap she's gotten from using IE while I'm here).

    So while AdAware is dling its thing I decide to go to Windowsupdate.com and get some crap dling before I leave (she's on dialup). As those pages are loading up I decide to check her monitor connection just incase thats loose. As I reach back behind I touched her usb cable going to her printer.

    *This is the most relavent part of solving this problem guys:
    When I bump that the printer (Epson Stylus 480SXU (Real cheap one)) it starts making noises like it does when you plug it in or connect it to the computer.
    When I hear that I look up at the monitor and try and move the mouse, the mouse cursor doesn't move, and I notice some slight artifacting on the screen.
    Shortly after I notice this the monitor shuts off, well its not off, but it does that thing like when you shut down windows, where its black but physically the monitor is still on.

    Hard drive and fans are still running though, I can hear them.

    So at this point I'm playing around with the printer usb cable and the monitor cable. I make sure the monitor one is pushed in properly, and I pulled out the printer usb connection completely.
    Everything seems fine, so I figure before I flip the switch I'll plug back in the USB printer.
    and thats when it happens, I hear the Windows sound for plugging in a USB device. So wow, windows is still alive....
    I'm sitting there perplexed for a bit and then I hear the sound AdAware makes when its done scanning, so that program survived too....

    I move the mouse around some more, hit alt-tab, hit ctrl alt del. None of which brought the video signal back up.

    So my diagnosis at this time is that either there is a short from the mobo to the case, or there is a short somewhere in the PSU. I'm hoping its the PSU because thats easiest to replace. But if the mobo isn't dying and is just touching something thats simple enough to fix once I figure out where that point of contact is.
    The reason I think its the PSU is because recently on my new system I was putting the side of the case back on and had built up a static charge. The side of the case discharged on something when I was placing it on and POOF my system shut down, and it would not power back on for a few minutes.
    Her system is exhibiting this symptom too. She says after 30 minutes or so she can turn it back on and it will be like normal again.
    The only reason so far I've thought of that its not the PSU is that I don't understand why only part of the power system would shut down. There was still power going to the motherboard and fans and hd. We know this because the fans still ran, the hd I never heard spin down, and Windows was still running based on the sounds.

    So until someone can convince me otherwise, I think my best bet is to try another PSU, will have to be at the earliest Saturday before I can do that, and likely not until Monday. So until then I'll await suggestions/thoughts.
     
  2. RealBlackStuff

    RealBlackStuff TS Rookie Posts: 6,503

    One place to look for a shorting against the chassis, would be that thin metal plate that surrounds all the PS2/sound/USB/parallel etc. ports on the pack of the PC. This has some very small 'lips' that fit around each individual port. They could easily make a false contact.
     
  3. Mictlantecuhtli

    Mictlantecuhtli TS Evangelist Posts: 4,345   +11

    Does it work normally without a printer?

    It could be the printer that doesn't work properly, too.
     
  4. SNGX1275

    SNGX1275 TS Forces Special Topic Starter Posts: 10,715   +397

    The printer works fine as far as I know. I left the printer connected because I thought she might need it... So, no, I don't know if it works fine without it.

    My guess is I could have bumped anything comming out of the computer and it would have done the same thing, but at this time I can't prove that cause I didn't have time to wait 30 minutes to try it again.
     
  5. Rick

    Rick TechSpot Staff Posts: 4,573   +65

    It sounds like you have diagnosed the cause of your symptoms... Having the printer plugged in is causing your blank screens.

    But the question remains whether or not the printer is to blame or the system.

    I know from experience, USB ports that are shorted can cause a system to shut off, freeze and even prevent it from turning on. It is very possible that some sort of electrical problem exists with the printer. That would be my first guess.

    I would attempt to eliminate the printer as the culprit by connecting another USB printer (if available). If your problem ceases to exist, then most likely it is a physical problem with the printer. If the problem still exists, then I would attempt to use a different cable. If the problem persists, the obvious cause is related to the system and is most likely a hardware issue.

    Power supply is an unlikely cause in my opinion, but I certainly won't rule it out. My best guess would be a damaged system board (electronics problems can cause some unpredictable behavior, just like this).

    From my experiences, I am unware of any software issues that cause this type of failure.
     
  6. SNGX1275

    SNGX1275 TS Forces Special Topic Starter Posts: 10,715   +397

    Last night I was able to bring the PC to my house, but I only had a few minutes to take a look at it. When I got it home I opened it up and reseated the video card. I also looked at where everything plugs into the mobo and saw that it looks like the USB or basically anything plugged in could short, because the mobo is fairly loose there. Also there either isn't a hole for a screw in the case, or its stripped. I didn't feel like taking the motherboard out of the case to see.

    Anyway I thought I'd test my theory on it shorting out, so I plugged it in and turned it on. As I did this I had some other stuff to get to so I didn't watch it boot, I came back a minute or 2 later to a black screen, the monitor was on, but just looked black. I hit reset and still no video.

    So not having much time I threw in another video card, and it booted up fine. I then plugged in a USB joystick and moved it a bit to try and see if something would short out if it got wiggled a bit. Everything stayed alive.
    I played around on it for a few minutes and everything seemed ok, I also left it on all night and it was still good this morning before I left for work.

    So I'm hoping there is just something wrong with the video card. Perhaps it isn't getting a good connection somewhere. The pins on it looked fine though, and I did make sure I had it seated well in the AGP slot.

    I think tonight I'm going to return the comp to her with the different video card and hopefully I won't get a call back from her with the same problem.
     
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